Abstract
Corn stover is emerging as a viable feedstock for producing bioethanol from renewable resources. Dilute-acid pretreatment of corn stover can solubilize a significant portion of the hemicellulosic component and enhance the enzymatic digestibility of the remaining cellulose for fermentation into ethanol. In this study, dilute H2SO4 pretreatment of corn stover was performed in a steam explosion reactor at 160°C, 180°C, and 190°C, approx 1 wt% H2SO4, and 70-s to 840-s residence times. The combined severity (Log10 [R o ] - pH), an expression relating pH, temperature, and residence time of pretreatment, ranged from 1.8 to 2.4. Soluble xylose yields varied from 63 to 77% of theoretical from pretreatments of corn stover at 160 and 180°C. However, yields >90% of theoretical were found with dilute-acid pretreatments at 190°C. A narrower range of higher combined severities was required for pretreatment to obtain high soluble xylose yields when the moisture content of the acid-impregnated feedstock was increased from 55 to 63 wt%. Simultaneous saccharification and fermentation (SSF) of washed solids from corn stover pretreated at 190°C, using an enzyme loading of 15 filter paper units (FPU)/g of cellulose, gave ethanol yields in excess of 85%. Similar SSF ethanol yields were found using washed solid residues from 160 and 180°C pretreatments at similar combined severities but required a higher enzyme loading of approx 25 FPU/g of cellulose.
Similar content being viewed by others
References
Grohmann, K., Himmel, M., Rivard, C., Tucker, M., Baker, J., Torget, R., and Graboski, M. (1984), Biotechnol. Bioeng. Symp. 14, 139–157.
Lin, K. W., Ladisch, M. R., Voloch, M., Patterson, J. A., and Noller, C. H. (1985), Biotechnol. Bioeng. 27, 1427–1433.
Weimer, P. J., Chou, Y. C. T., Weston, W. M., and Chase, D. B. (1986), Biotechnol. Bioeng. Symp. 17, 5–18.
Rolz, C., de Arriola, M. C., Valladares, J., and de Cabrera, S. (1987), Process Biochem. 22, 17–23.
Torget, R., Werdene, P., Himmel, M., and Grohmann, K., (1990), Appl. Biochem. Biotechnol. 24/25, 115–126.
Grethlein, H. E. and Converse, A. O. (1991), Bioresour.e Technol. 36, 77–82.
Chang, V. S. and Holtzapple, M. T. (2000), Appl. Biochem. Biotech. 84–86, 5–37.
Torget, R., Himmel, M. E., and Grohmann, K. (1992), Appl. Biochem. Biotech. 34/35, 115–123.
Esteghlalian, A., Hashimoto, A. G., Fenske, J. J., and Penner, M. H. (1997), Bioresour. Technol. 59, 129–136.
Schell, D. J., Walter, P. J., and Johnson, D. K. (1992), Appl. Biochem. Biotechnol. 34/35, 659–665.
Torget, R., Walter, P., Himmel, M. E., and Grohmann, K. (1991), Appl. Biochem. Biotechnol. 28/29, 75–86.
Tucker, M. P., Farmer, J. D., Keller, F. A., Schell, D. J., and Nguyen, Q. A. (1998), Appl. Biochem. Biotech. 70–72, 25–35.
Nguyen, Q. A., Dickow, J. H., Duff, B. W., Farmer, J. D., Glassner, D. A., and Ibsen, K. N. (1996), Bioresour. Technol. 59, 189–196.
Chum, H. L., Johnson, D. K., Black, S. K., and Overend, R. P. (1990), Appl. Biochem. Biotechnol. 24/25, 1–14.
Nguyen Q. A., Tucker, M. P., Keller, F. A., and Eddy, F. P. (2000), Appl. Biochem. Biotech. 84–86, 561–570.
Kim, K. H., Tucker, M. P., and Nguyen, Q. A. (2002), Biotechnol. Prog. 18, 489–494.
Dowe, N. and McMillan, J. (2001), NREL Analytical Procedure, No. 008, National Renewable Energy Laboratory, Golden, CO; (Website: http://www.ott.doe.gov/biofuels/analytical_methods.html#LAP-002).
Nguyen, Q. A., Tucker, M. P., Boynton, B., Keller, F. A., and Schell, D. J. (1998), Appl. Biochem. Biotechnol. 70–72, 77–87.
Ruiz, R. and Ehrman, T. (1996), NREL Analytical Procedure, No. 014, National Renewable Energy Laboratory, Golden, CO. (Website: http://www.ott.doe.gov/biofuels/analytical_methods.html#LAP-014)
Hames, B. R., Thomas, S. R., Sluiter, A. D., Roth, C. J., and Templeton, D. W. (2003), Appl. Biochem. Biotechnol. 105–108, 5–16.
Hamilton, F. and Leopold, B., eds. (1993), in Pulp and Paper Manufacture, vol. 3, Joint Textbook Committee of the Paper Industry of the United States and Canada, Atlanta, p. 119.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tucker, M.P., Kim, K.H., Newman, M.M. et al. Effects of temperature and moisture on dilute-acid steam explosion pretreatment of corn stover and cellulase enzyme digestibility. Appl Biochem Biotechnol 105, 165–177 (2003). https://doi.org/10.1385/ABAB:105:1-3:165
Issue Date:
DOI: https://doi.org/10.1385/ABAB:105:1-3:165